Q: New iMac 27inch screen flickering/tearing/shutoff

Hello everyone. I have been following this thread since early Dec. Have read all posts.

Received my week 50 i5 on Dec 16 . First flicker came three days later. Very brief, if you immediately put to sleep and wake up. If not put to sleep, will get worse. Once the menu bar briefly flashed to middle of screen when I didn't immediately put to sleep. A couple of short lived blackouts also. On one occasion I even had scrambled horizontal color lines very much like old analog tvs when they had a horizontal adjustment dial. As with other problems, pressing power button, letting it sleep for a couple of seconds, fixed the problem for the rest of the day. Harddrive makes stomach rumbling gurgling sound at slightest use. Not loud, and unnoticeable if music is playing.

I realize that everthing I noted above is nothing new to this thread. One difference is that I use a large pictures folder as screensaver. I have never had a single flicker while this screensaver is displaying my pictures, but everytime I go to the computer while the screensaver is running, press the mouse to stop screensaver and begin any other activity, I get a flicker within 5 min which is stopped by quick sleep cycle. No more flickers that day. At first it seemed that the flicker was every three or four days, but now seems to happen once a day upon exiting screensaver.

I called AppleCare shortly after first flicker in mid Dec. Got a case #, did resets etc.

I will continue to follow this thread. My first Mac and I continue to be happy other than the flicker.

I have a question for those of you who may be more technically savvy than me.

Assuming that Apple is able to create a firmware fix for the screen flicker and/or the yellow tinge, and assuming that this fix is some kind of post processing mechanism, considering the size of these LCD screens, do you think that the fix might have a negative effect on some of the other processes which are involved in drawing the screen? More specifically, I am wondering if borrowing from Peter to pay Paul might:

1. put added stress on the LCD panel.

2. slow down screen-drawing, even if it imperceptible to the human eye.

3. in the long run, shorten the life of the LCD panel.

As I said, I am far from a technical whiz, but if, for example, the approach that Apple takes were to be something like trying to recalibrate every single defective pixel or sub pixel that is not displaying the proper color -- the yellow tinge -- so that we see white as white, and not as dirty white or yellow, it seems to me that it would place a heavy burden on the processors, as well as on the LCD panel itself.

Alright you techno giants . . . go ahead and tell me that I don't know what I am talking about. I probably don't.

"Apple is known for quality do you really think they would let everyone suffer like this?"



They just have!

Has anyone tried a pixel scrubbing software to try and fix the yellow tinge? Here is the software that I am talking about:

http://www.apple.com/downloads/macosx/icons_screensavers/lcdscrub.html

I know its for LCD's but I'm wondering if it would work for LED's.

the imac is LCD!
It's LED backlit....

Joel, what brand Hard Drive do you have? I have the Hitachi 500 GB & your description of the sound is right on to the sound mind makes. Very Low but if Music is not playing you can hear it.
I have 21.5" NVidia Week 51 iMac. t also has Yellow tinge, right side of screen.

I installed it. It's in my Screensaver List but how do I get into the options of different Scrubs. I can't find the Utility for Preferences, it just put it in Screen saver. Did I Install incorrectly. I don't think so.

I figured it out.
Which selection would you choose for a Yellow Screen? There are many Screensavers to Choose from. Anyone know? Thanks!

I don't tell you ... at the end you have an explosion

Yea right! I wouldn't doubt it! You have to buy it if you want it to run for 6-24 hours as Instructed. Apple Suggests the White Only mode. I made my own version of this on my iBook. Took a White Keynote Slide & put it in Pictures folder. Ran it for hours. It got rid of Screen Burn. Same thin this is doing.

I just want to comment on the opinions of some people here regarding the quality of LG's LCDs.

I work as an Audiovisual project manager for a firm that is specialized in designing museums and exibitions around the world.
Among other things that I do, I specify and approve the equipments choices for our projects.
We usually use PRO grade equipments for our projects.
They have better quality and longer lasting components.

I am not saying that LG makes the best and top quality electronics around but they are certainly not the cheapest or lowest quality maker around.

LG is a manufacturer of LCD panels.
They actually make the panels that are used by brands like:
Samsung, LGE, Philips, Vizo, Panasonic, Toshiba, Hitachi, AmTRAN and Skyworth

Most of these brand do not make LCD panels.
They buy the panels fron makers such as LG and assemble them with their own components to make TVs or monitors.

So if your brand new LCD TV is from one of these brands, you probably have an LG LCD panel in there.

Sharp Japan, makes panels for Toshiba, Philips, Sony, Pioneer (LCD) and Sharp

Samsung for JVC, Samsung, Sony, Philips, Sanyo and Panasonic

Sony, who for some is the best brand around (not for me!) does not even make their own panels!
Some of their low end TVs are no even made by them but sub contracted to others.

All this to say that it's not because it's made by LG that it's automatically not good.
LG,like most major brands, has low end products and high end products.
The panels in our iMacs could have been made by Sharp or Samsung or some other less known Korean or Taiwanese maker and not be of better quality.

Many of you here probably have TVs or monitors that use LG LCD panels and are very happy with them.

The real problem is that when companies like Apple make new machines they have to make decisions regarding the quality of components versus the sale price of the machines.
And it looks like this time Apple did not choose or was not provided with good enough components, be it the cables, video card or the LCD panel it self.

I seriously doubt that the yellowing problem as anything to do with image persistence or burn in. Image persistence is a problem that shows up when you leave the same image on screen for many,many,many days if not months!
You will be left with a "ghost" of that image on your screen even after removing the image.

You cant have burn in or image persistence on screens that are just a few weeks or months old.

My thoughts exactly, Nexus600. I think we are dealing with a very different issue here. If I have properly understood some of the previous more technical posts by a few folks, the flicker problem has something to do with some kind of miscommunication problem, or timing problem, between the GPU and the LCD panel, while the yellow tinge is a result of an actual physical defect in a layer of the LCD panel itself.

Am I close?

Seagate.....so go figure huh.....I didn't hear it at first, although that does beg the comment/question "I notice the sound more now because I am aware of it....or.....is it getting louder?

Gettting back to the premise of this thread, as I noted in my original post today, why would my screen _never flicker_ during multigigabyte screensaver? Sometimes the screen-saver runs for 4 or 5 hours.

Joel, my last one was a Seagate & it was extremely Quiet. Pazuita mentioned on here that one brand is not quieter than the other. Each Hard Drive sounds is Individual. In other words, 2 identical HD's. One makes noise, one does not. But I don't think there is anything wrong with our Hard Drives. I did a check i Disc Utility & all is OK.

I do not have the answer to your screen saver question. That is Strange.